jonrobertson

Nope. I used my domain name. Bitdefender and Chrome get cranky with my SSL certificate if I access my server using the local IP address. ??

A friend (and a Linux guru) suggested that I try accessing my site from outside my LAN because the issue may with my LAN rather than the Pi itself. Over the weekend, I was able to do some testing from another friend’s house. And, lo and behold, I did not have a single ERR_CONNECTION_TIMED_OUT while accessing my site or the admin pages.

After a bit more Googling, I’ve learned that the AT&T U-Verse router/gateway that I have (nvg510) has an issue with DNS. (How to change dns settings to fix nvg510 issues). The nvg510 does not wait long enough for a response from the DNS server. This makes sense, as I often would see the ERR_CONNECTION_TIMED_OUT immediately, as though the request never made it past my router.

It appears the best solutions involve configuring the nvg510 to be a bridge (modem only) and either buying another router, or, perhaps configuring my Pi to be the router for my LAN.

I’m still very green with Linux networking and don’t do network configuration often enough to be that proficient at it anyway. So I’ll likely try buying another router.

Still getting ERR_CONNECTION_TIMED_OUT errors using lighttpd instead of apache, although not as many. Oh well, I’m just talking to myself at this point. If I really want a site, I should probably create one at www.ads-software.com and forgo the idea of running a web server on my pi.

The WD NVMe SSD came in today. I followed a process I found online to copy my SD card to the SSD and set the SSD as root. The SSD is 5.6 times faster according to the bookmark I took of the SD card (James A. Chambers Raspberry Pi Storage Benchmarks).

Unfortunately, I still see several ERR_CONNECTION_TIMED_OUT errors on every page of my WP site, both the user site and the admin pages.

I think my next step is to try to replace apache with lighttpd.

I ordered a WD_Black SN750 500GB NVMe SSD and a USB 3.1 enclosure from Amazon. They will arrive on Thursday. I’m going to copy my SD card to it and configure Raspbian to use the SSD for my root partition.

I’m anxious to see how much of a performance improvement this provides and whether that resolves the timeout errors.

Increasing allocated PHP memory to 256MB did not resolve the issue. I don’t think it helped at all. I’m using a PHP script named opcache.php to view PHP memory usage and cache utilization.

opcache opcache.memory_consumption is configured at 128MB. opcache is using 39MB with almost 89MB free. There are 72,162 cache hits versus 1,145 cache misses (98.44% cache hit rate). Seems to me that the cache is working well.

There is also a 6MB buffer listed. I thought this was opcache.interned_strings_buffer, but that is configured to the default of 8MB. What is the 6MB buffer and should I be concerned about it?. Of that 6MB, 4.47MB is used and 1.53MB is free.

I ran the script at memory_get_peek_usage docs in CLI and it reported 717 MiB as my max memory usage.

I realize it is likely an issue with the configuration of my Raspberry Pi 4/Apache/MySQL/PHP. However, the problem is specifically impacting my self-hosted WordPress site. I don’t have any issues with other web pages or phpMyAdmin.

So I posted here hoping that someone with extensive WordPress experience could give me some guidance.

I’ve done those things, and more.

My RPi is sitting 2 feet from me

I am my hosting provider.

WP Debug is enabled. That is where I found the “PHP Notice” messages. Does PHP have its own error log? Or would all PHP errors go to either the apache error.log or WP debug log?

I have Query Monitor installed. I neglected to mention that earlier because it is hard to keep track of everything that I’ve tried. I’ve only used it for about 15 minutes and I haven’t taken the time to find a good “how-to” article to really learn how to use it. But from what I could determine, 4% of the queries are taking between 0.005 and 0.008 seconds. The rest are taking less than 0.002 seconds.

I’ll bump up the PHP memory. From what I can tell, most of the Pi’s 4GB is not being used. Although I don’t have any knowledge of Linux memory usage/management like I do for Windows.

Duh… My apologies. I’ve been in front of this monitor for too long. I just realized the message in appache’s error.log isn’t an error. It’s just an output of the command used to start the apache daemon/service.

Would PHP log errors to somewhere aside from /var/log/apache2/error.log or the WP debug log?

error.log in /var/log/apache2 contains this when I restart apache using “sudo service apache2 restart”:

[Sun May 17 09:47:49.128577 2020] [core:notice] [pid 25837] AH00094: Command line: '/usr/sbin/apache2'

The WP debug log contains a couple of entries that I don’t know how to resolve. I haven’t modified any source directly. I tried re-installing via the admin update page but that did not resolve these:

PHP Notice:  Undefined index: hook_suffix in /var/www/html/wp/wp-admin/includes/class-wp-screen.php on line 223
PHP Notice:  Array to string conversion in /var/www/html/wp/wp-content/plugins/health-check/includes/class-health-check-debug-data.php on line 1172.

And there is a theme related error. I’m going to reach out to the theme developer for this one:
PHP Notice: Undefined variable: widget_footer_width in /var/www/html/wp/wp-content/themes/potter/inc/customizer/styles.php on line 2567

My apologies. I still get timeouts if I switch to troubleshooting mode, with plug-ins disabled and using the TwentyTwenty theme.

I came across this useful storage benchmark: James A. Chambers Raspberry Pi Storage Benchmarks

He collects the results and provides them on his website. According to his benchmark, my SD card scored 1386. The best performing SD card in his benchmarks scored 1590.

Based on this, I don’t think my SD card is the cause of the ERR_CONNECTION_TIMED_OUT responses. Unfortunately, I can’t tell what is.

I’ve also learned that as I move around wp-admin, ERR_CONNECTION_TIMED_OUT messages appear in Chrome’s console even if the page loads correctly. Sometimes the page will partially load but not finish due to the timeouts.

I’ve done those things, and more. Increased memory in php.ini to 128MB, increased WP_MEMORY_LIMIT to 128MB and WP_MAX_MEMORY_LIMIT to 128MB, and increased the PHP execution time to 60 seconds.

I’ve checked the Apache, PHP, and MySQL caches. They are enabled, working, and have plenty of memory available. I’ve also installed and activated the WP Super Cache and Autoptimize plug-ins.

I’ve monitored the Pi itself using htop and dstat tools. I’m still learning Linux and these tools are new to me, so I’m still figuring out how to use them well. Using the default options, I don’t see anything alarming.

One area that I need to investigate is the SD card I/O performance while I’m working on my site.